Change the return values for these functions - now they return the unmarshaled result plus
the size of the unmarshaled result in bytes, so the caller could re-slice the src for further unmarshaling.
This improves performance of these functions in hot loops of VictoriaLogs a bit.
- Consistently return the first `limit` log entries if the total size of found log entries doesn't exceed 1Mb.
See app/vlselect/logsql/sort_writer.go . Previously random log entries could be returned with each request.
- Document the change at docs/VictoriaLogs/CHANGELOG.md
- Document the `limit` query arg at docs/VictoriaLogs/querying/README.md
- Make the change less intrusive.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5674
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5778
This should smooth CPU and RAM usage spikes related to these periodic tasks,
by reducing the probability that multiple concurrent periodic tasks are performed at the same time.
- Move uniqueFields from rows to blockStreamMerger struct.
This allows localizing all the references to uniqueFields inside blockStreamMerger.mustWriteBlock(),
which should improve readability and maintainability of the code.
- Remove logging of the event when blocks cannot be merged because they contain more than maxColumnsPerBlock,
since the provided logging didn't provide the solution for the issue with too many columns.
I couldn't figure out the proper solution, which could be helpful for end user,
so decided to remove the logging until we find the solution.
This commit also contains the following additional changes:
- It truncates field names longer than 128 chars during logs ingestion.
This should prevent from ingesting bogus field names.
This also should prevent from too big columnsHeader blocks,
which could negatively affect search query performance,
since columnsHeader is read on every scan of the corresponding data block.
- It limits the maximum length of const column value to 256.
Longer values are stored in an ordinary columns.
This helps limiting the size of columnsHeader blocks
and improving search query performance by avoiding
reading too long const columns on every scan of the corresponding data block.
- It deduplicates columns with identical names during data ingestion
and background merging. Previously it was possible to pass columns with duplicate names
to block.mustInitFromRows(), and they were stored as is in the block.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4762
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/4969
- Compare the actual free disk space to the value provided via -storage.minFreeDiskSpaceBytes
directly inside the Storage.IsReadOnly(). This should work fast in most cases.
This simplifies the logic at lib/storage.
- Do not take into account -storage.minFreeDiskSpaceBytes during background merges, since
it results in uncontrolled growth of small parts when the free disk space approaches -storage.minFreeDiskSpaceBytes.
The background merge logic uses another mechanism for determining whether there is enough
disk space for the merge - it reserves the needed disk space before the merge
and releases it after the merge. This prevents from out of disk space errors during background merge.
- Properly handle corner cases for flushing in-memory data to disk when the storage
enters read-only mode. This is better than losing the in-memory data.
- Return back Storage.MustAddRows() instead of Storage.AddRows(),
since the only case when AddRows() can return error is when the storage is in read-only mode.
This case must be handled by the caller by calling Storage.IsReadOnly()
before adding rows to the storage.
This simplifies the code a bit, since the caller of Storage.MustAddRows() shouldn't handle
errors returned by Storage.AddRows().
- Properly store parsed logs to Storage if parts of the request contain invalid log lines.
Previously the parsed logs could be lost in this case.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4737
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/4945
* lib/logstorage: prevent from panic during background merge
Fixes panic during background merge when resulting block would contain more columns than maxColumnsPerBlock.
Buffered data will be flushed and replaced by the next block.
See: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4762
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/logstorage: clarify field description and comment
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
